Key hinge for woodwind instruments



July 30, 1968 R. c. SEAMAN KEY HINGE FOR WOODWIND INSTRUMENTS Filed Sept. 6. 1966 l8 4 232/ /6 a i HTTOR/UEY United States Patent 3,394,624 KEY HINGE FOR WOODWIND INSTRUMENTS Roy C. Seaman, Paterson, NJ. (4454 W. 141st St., Hawthorne, Calif. 90250) Filed Sept. 6, 1966, Ser. No. 577,424 7 Claims. (Cl. 84-382) My invention relates generally to musical instruments, and is directed particularly to an improved key hinge for woodwind instruments.

At the present time valve key shafts are hinged for axial rotation either by means of pivot screws extending into pointed recesses in each end of the shaft, the shaft being of solid metal, (usually used when shaft is long), or by the use of tubular shafts journalled on central fixed rods (usually used when shaft is short). Both of these hinge mechanisms need lubrication, and are subject to wear, especially if proper lubrication is not maintained. In the case of solid shaft keys, wear at the pivot points results in looseness which cannot readily be corrected because the worn interacting pivotal surface will not hold the lubricant. In the case of tubular shafts Wear results in rattle that can be corrected for only by expensive repair or replacement.

It is accordingly the principal object of this invention to provide an improved key hinge for woodwind instruments which will obviate the above-described deficiencies of hinged valve keys.

It is another object to provide an improved key hinge for woodwind instruments which needs no lubrication, which will be long-wearing and quiet in use, and wherein the hinge bearing parts can be easily and inexpensively replaced if necessary.

Yet another object is to provide a new and improved pivotal bearing for woodwind instrument valve keys that is readily adaptable to use in the modification of ordinary key hinges as well as to incorporation in the manufacture of new keyed musical instruments such as, for example, saxophones, clarinets and bassoons.

A more specific object of the invention resides in the use of tough, synthetic plastic bushings as inserts in axial recesses formed in the ends of the valve key shafts and provided with axially-extending frusto-conical pivotal seats received within which are the usual pivot screws.

Other objects, features and advantages of the invention will be apparent from the following description when read with reference to the accompanying drawings. In the drawings, wherein like reference numerals denote corresponding parts throughout the several views:

FIG. 1 is a partial view of a woodwind instrument, such as a clarinet, equipped with a key hinge mechanism embodying the invention;

FIG. 2 is a longitudinal cross-sectional view of the hinge mechanism illustrated in FIG. 1, taken along the line 2-2 thereof in the direction of the arrows; and

FIG. 3 is an exploded view of one end of the hinge mechanism shown in FIG. 2, also shown in longitudinal cross-section.

Referring now in detail to the drawings, in FIGS. 1 and 2 designates, generally, a key hinge mechanism for woodwind instruments, the same being illustrated by way of example as a typical clarinet key. The key hinge mechanism 10 comprises the key shaft 11, preferably of solid metal such as brass, afiixed along which are the usual finger-piece and valve elements 12 and 13, respectively. The ends of the key shaft 11 are axially-bored to provide cylindrical recesses 14 within which bearing members 15 are fitted and frictionally retained, as in hereinbelow more fully described. The bearing members 15 are formed of a tough synthetic plastic material such as TEFLON, and comprise a cylindrical shank portion 16 integrally formed at one end with an annular flange 17. The flanged end of the bearing member 15 is formed with an inwardly-convergent, coaxial, frusto-conical recess 18 extending approximately half way along the length of said bearing member and merging at its inner end with a cylindrical bore 19 extending axially through the opposite end of said bearing member. The shank portions of the bearing members 15 are of such outer diameter as to fit snugly within the recess 14 at the opposite ends of the key shaft 11, to be retained therein by frictional ngagement. The flange 17 of the bearing members 15 define annular shoulders 20 which seat against the outer ends of the key shaft 11, the external diameters of said annular shoulders preferably being the same as that of said key shaft.

The key shaft 11 with the bearing members 15 assembled thereto at each end are journalled between hinge pivot screws 21 threadingly received in threaded openings 23 in support posts 22 aflixed to the body of the musical instrument to which the invention is applied. The hinge pivot screws 21 are formed with conical end portions 24 having the same taper as that of the frustoconical recesses 18 in the bearing members 15 so that when assembled thereto in interfitting relation, as illustrated in FIG. 2, said frusto-conical recess will bear along their entire surfaces in face-to-face relation against the outer surfaces of said conical end portion. The hinge pivot screws 21 and the support posts 22 are preferably formed of brass.

While I have illustrated and described herein only one form in which my invention may conveniently be embodied in practice, it is to be understood that this embodiment is given by way of example only, and not in a limiting sense.

What I claim as new and desire to secure by Letters Patent is:

1. In a key hinge for musical instruments of the type having an axially rotatable key shaft, the combination comprising, an axial bore in each end of the key shaft, a cylindrical bearing member of a tough, synthetic plastic material removably fitted in each of said end bores, said bearing members each being formed with a longitudinallyextending through opening, said through opening comprising an inwardly-divergent, frusto-conical outer end recess, and a pair of relatively fixed, metal pivot screws having conical end portions in face-to-face contact with one each of the surface portions of said frusto-conical outer end recess portions of said bearing member through openings.

2. A key hinge for musical instruments as defined in claim 1 wherein said cylindrical bearing members are each formed with an annular flange at their outer end providing annular shoulders seatable against outer end portions of said key shaft.

3. A key hinge for musical instruments as defined in claim 2 wherein said bearing member through openings each further comprises a cylindrical bore merging with the inner end of one each of said frusto-conical recesses and extending through the inner end of said bearing members.

4. A key hinge for musical instruments as defined in claim 3 wherein said pivot screws are threadingly received in support posts adapted to be secured in spaced relation along the body of a musical instrument.

5. A key hinge for musical instruments as defined in claim 3 wherein said frusto-conical recesses extend substantially one-half the axial distance through said bearing members.

6. A key hinge for musical instruments as defined in claim 5 wherein said bearing members are fabricated of Teflon.

7. A bearing member for musical instrument key hinges References Cited comprising, a cylindricalshank member formed with an i V UNITED STATES PATENTS annular flan e at one end, and an axial o enin through said bearing member and comprising an inwfrdly-con- 3240095 3/1966 Stemway 84-251 vergent frusto-conical portion extending substantially half- I N PATENTS way therethrough from said flanged end, and a cylindrical 1,121 158 7 /1956 m bore portion merging with the inner end of said frustoconical portion and extending through the opposite end ROBERT R 111., Primary Exammer,

of said bearing member. GARY M. POLUMBUS, Assistant Examiner. 

1. IN A KEY HINGE FOR MUSICAL INSTRUMENTS OF THE TYPE HAVING AN AXIALLY ROTATABLE KEY SHAFT, THE COMBINATION COMPRISING, AN AXIAL BORE IN EACH END OF THE KEY SHAFT, A CYLINDRICAL BEARING MEMBER OF A TOUGH, SYNTHETIC PLASTIC MATERIAL REMOVABLY FITTED IN EACH OF SAID END BORES, SAID BEARING MEMBERS EACH BEING FORMED WITH A LONGITUDINALLYEXTENDING THROUGH OPENING, SAID THROUGH OPENING COMPRISING AN INWARDLY-DIVERGENT, FRUSTO-CONICAL OUTER END 